ゲーム開始前に死ぬモブ悪役皇子に転生した俺～推しヒロインの妹と幸せになるために最弱魔法【闇刃】を過剰な努力で極め抜いたら、最強のぶっ壊れ性能と化していた件〜

I Reincarnated as a Mob Villain Prince Who Dies Before the Game Starts ~ In Order to Be Happy with My Favorite Heroine’s Younger Sister, I Overcame My Weakest Magic [Dark Blade] with Excessive Effort, and It Became the Strongest Broken Power ~

Huh? When did my fallen-into-darkness little sister start obsessively worshiping me like a yandere? I, Luke, the 5th prince of the Celestia Empire, had a younger sister. She was Diana, the world’s cutest sister who loved me. However, she was fated to fall into darkness and die. This is the world of the RPG game…

ゲーム開始前に死ぬモブ悪役皇子に転生した俺～推しヒロインの妹と幸せになるために最弱魔法【闇刃】を過剰な努力で極め抜いたら、最強のぶっ壊れ性能と化していた件〜 (Associated Names)

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